Differential and bearing arrangement

ABSTRACT

An axle assembly with an axle housing with a pair of bearing journals, a differential assembly disposed between the bearing journals, a pair of differential bearings and a pair of hollow adjusters that can be threaded into the bearing journals to preload the differential bearings and control gear lash between a pinion and a ring gear. Retaining members can be non-rotatably engage to the hollow adjusters and can be press-fit into counterbores in the outboard sides of the bearing journals. The axle housing can include an unitarily formed differential housing with a body and an axle tube structure, and a first axle tube that can be discretely formed and coupled to the body.

INTRODUCTION

The present invention generally relates to axle assemblies. Moreparticularly, the present invention relates to an axle assembly that canbe packaged into a relatively narrow location and a related method formaking an axle assembly.

Automotive drive axles can include an axle housing, a pair of axleshafts, an input pinion, and a differential assembly that can include adifferential case, a ring gear mounted to the differential case, and agearset that is disposed within the differential case. The differentialcase can be mounted in the axle housing for rotation about a first axis.The input pinion can be received by the axle housing for rotation abouta second axis that is generally perpendicular to the first axis. Thepinion can meshingly engage the ring gear.

In some situations, it may be difficult to fit or package an axleassembly into a vehicle due to the size of the axle housing.Accordingly, there remains a need in the art for an improved axleassembly that may be more easily packaged into a vehicle.

SUMMARY

In one form the present teachings provide a an axle assembly with anaxle housing, a pinion, a differential assembly, a pair of first bearingportions, a pair of adjusters, a pair of second bearing portions and apair of retaining members. The axle housing defining a pair of bearingjournals and a pinion bore. The differential bearing journals having athreaded bore formed therethrough that is generally perpendicular to thepinion bore. Each one of the differential bearing journals having anoutboard side opposite the other one of the differential bearingjournals and a counterbore that is concentric with the threaded bore isformed in each of the outboard sides. The pinion is rotatably mounted inthe pinion bore. The differential assembly has a differential case, agearset received in the differential case, and a ring gear meshinglyengaged to the pinion. The differential case includes a pair of bearingmounts. The differential bearings having a first bearing portion andsecond bearing portion. Each first bearing portion being coupled to anassociated one of the bearing mounts and including a first bearing raceand a set of bearing members that are mounted on a respective one of thefirst bearing races. The hollow adjusters having a threaded body portionand an adjustment portion. Each of the hollow adjusters being coupled tothe axle housing such that its threaded body portion is threadablyengaged to the threaded bore of an associated one of the differentialbearing journals. The adjustment portions having a non-circular featurethat is configured to be engaged by a tool for rotating the hollowadjusters. Each second bearing portion having a second bearing race thatis disposed between one of the hollow adjusters and an associated one ofthe sets of bearing members. Each retaining member being received on anassociated one of the hollow adjusters and engaging the non-circularfeature to inhibit relative rotation therebetween. Each of the retainingmembers being press-fit into an associated one of the counterbores toinhibit relative rotation between the retaining members and the axlehousing.

In another form the present teachings provide an axle assembly thatincludes an axle housing, a pinion, a differential assembly, a pair offirst bearing portions, a pair of hollow adjusters, a pair of secondbearing portions and a pair of retaining members. The axle housing has adifferential housing, a first axle tube and a second axle tube. Thedifferential housing defines a pair of bearing journals and a pinionbore. The differential bearing journals are integrally formed with thedifferential housing and are non-separable from a remainder of thedifferential housing. The differential bearing journals having athreaded bore formed therethrough that is generally perpendicular to thepinion bore. The first axle tube is separately formed and removablycoupled to the differential housing. The second axle tube is integrallyformed with the differential housing and is shorter than the first axletube. The pinion is rotatably mounted in the pinion bore. Thedifferential assembly having a differential case, a gearset received inthe differential case, and a ring gear meshingly engaged to the pinion.The differential case includes a pair of bearing mounts. Each of thefirst bearing portions is coupled to an associated one of the bearingmounts and includes a first bearing race and a set of bearing membersthat are mounted on a respective one of the first bearing races. Thehollow adjusters have a threaded body portion and an adjustment portion.Each of the hollow adjusters is coupled to the axle housing such thatits threaded body portion is threadably engaged to the threaded bore ofan associated one of the differential bearing journals. Each secondbearing portion has a second bearing race that is press-fit to one ofthe hollow adjusters and the second bearing portions are disposedbetween the hollow adjusters the sets of bearing members. The retainingmembers are received on the hollow adjusters and engage the non-circularfeature to inhibit relative rotation between the axle housing and thehollow adjusters.

In yet another form the present teachings provide a method forassembling an axle assembly. The method includes: providing adifferential housing with a pair of differential bearing journals;installing a pinion into the differential housing; positioning adifferential assembly between the differential bearing journals;threading a hollow adjuster into each of the differential bearingjournals; installing a retaining member over each of the hollowadjusters, each retaining member engaging a non-circular feature on arespective one of the hollow adjusters; and pressing each of theretaining members into a counterbore formed on an associated one of thedifferential bearing journals, the retaining members engaging thedifferential housing to inhibit relative rotation therebetween.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a schematic illustration of a vehicle having an axle assembly(i.e., a front axle assembly) constructed in accordance with theteachings of the present disclosure;

FIG. 2 is a rear exploded view of a portion of the vehicle of FIG. 1illustrating the front axle assembly in more detail;

FIG. 3 is a sectional view of the front axle taken longitudinally alongthe rotational axis of the differential; and

FIG. 4 is an exploded perspective view of the front axle assembly.

DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS

With reference to FIG. 1 of the drawings, a vehicle having an axleassembly (i.e., front axle assembly 32) constructed in accordance withthe teachings of the present disclosure is generally indicated byreference numeral 10. The vehicle 10 can include a driveline 12 that ispowered (i.e., driven) by a power train 14. The power train 14 caninclude an engine 16 and a transmission 18. The driveline 12 can includea transfer case 22 or other power distributing device, a rear propshaft24, a rear axle assembly 26, a plurality of rear wheels 28, a frontpropshaft 30, a front axle assembly 32 and a pair of front wheels 34.The engine 16 can be mounted in an in-line or longitudinal orientationalong the longitudinal axis of the vehicle 10 and its output can becoupled to the input of the transmission 18 in a conventional manner totransmit rotary power (i.e., drive torque) therebetween. Thetransmission 18 can include an output and a gear reduction unit that canbe employed to couple the transmission input to the transmission outputat a selected gear or speed ratio.

The transfer case 22 can be a conventional transfer case and can becoupled to the transmission 18 configured to transmit rotary power tothe rear axle assembly 26 and the front axle assembly 32 in a desiredmanner. For example, the transfer case 22 can be operable in a firstmode in which rotary power is transmitted only to the rear axle assembly26 and in a second mode in which drive torque is allocated between therear and front axle assemblies 26 and 32 in a predetermined manner.

The rear propshaft 24 is conventional and couples a rear output of thetransfer case 22 to an input of the rear axle assembly 26, which is alsoconventional. The rear wheels 28 are coupled to and driven by the rearaxle assembly 26 in a conventional manner. The front propshaft 30 isconventional and couples a front output of the transfer case 22 to thefront axle assembly 32. The front wheels 34 are coupled to and driven bythe front axle assembly 32.

With reference to FIGS. 2 through 4, the front axle assembly 32 caninclude an axle housing 50, a pinion 52, a differential assembly 54, apair of adjusters 56, a pair of retaining members 58 and a pair ofdifferential bearings 60, each of which having a first bearing portion62 and a second bearing portion 64. The axle housing 50 can include adifferential housing 70 and a first axle tube 72. The differentialhousing 70 can include a body portion 74 and a second axle tube or axletube portion 76.

With specific reference to FIGS. 3 and 4, the body portion 74 caninclude a wall member 80, a first bearing journal 82 and a secondbearing journal 84. The wall member 80 can define a cavity 86 as well asa pinion bore 88 and an axle shaft aperture 90. The axle tube portion 76can be integrally formed with the wall member 80 and can define an axletube bore 92 that can be arranged about the axis of the axle shaftaperture 90. The first and second bearing journals 82 and 84 can bedisposed in the cavity 86 inwardly of the wall member 80 and can beintegrally formed with and non-removably coupled to the wall member 80.A threaded bore 94 can be formed through the first and second bearingjournals 82 and 84 about a first axis 96. The first axis 96 can becoincident with the axes of the axle shaft aperture 90 and the axle tubebore 92. Each of the first and second bearing journals 82 and 84 caninclude an outboard sidewall 98 that can be positioned on a sideopposite the other one of the first and second bearing journals 82 and84. A counterbore 100 can be formed into each of the outboard sidewalls98 concentric with the threaded bore 94. In the particular exampleprovided, the counterbore 100 is a circular in shape. The pinion bore 88can be disposed about a second axis 102 that can be generallyperpendicular to the first axis 96. The pinion 52 can be received in thepinion bore 88 and supported on bearings 104 for rotation about thesecond axis 102. The axle tube portion 76 can be a hollow-structure thatcan be integrally formed with the body portion 74. An end of the axletube portion 76 opposite the body portion 74 can define a seal bore 108.

The first axle tube 72 can include a hollow tube portion 120 and aflange member 122 that can extend about the tube portion 120. A sealbore 124 can be formed in an end of the tube portion 120 opposite theflange member 122. The flange member 122 can be removably coupled to thebody portion 74 in a manner that aligns the hollow interior of the firstaxle tube 72 (including the seal bore 124) to the first axis 96. In theparticular example provided, a counterbore 130 formed in the wall member80 is sized to receive a lip 313 on the flange member 122; the lip 131on the flange member 122 and the counterbore 130 are sized to align thefirst axle tube 72 to the first axis 96. Threaded fasteners 132 can beemployed to fixedly but removably couple the flange member 122 to thewall member 80.

The differential assembly 54 can include a differential case 150, a ringgear 152, and a gear set 154. The differential case 150 can define acase body 160 and a case flange 162 that can extend radially outwardlyfrom the case body 160. The case body 160 can define a case cavity 164,into which the gear set 154 is received, and a pair of first bearingmounts 168. The ring gear 152 can be coupled to the case flange 162 byany suitable means, such as laser welding or via a plurality of threadedfasteners 170. The gear set 154, which can include a pair of side gears172 and a pair of pinion gears 174, can be received in the case cavity164. The first bearing mounts 168 can be counterbores 180 that can beformed into the opposite sides of the differential case 150. Thecounterbores 180 can be sized to receive the first bearing portion 62,which can include a first bearing race 182, such as an outer bearingrace, and a set of bearings 184, such as a set of rollers. The firstbearing races 182 can be press-fit into the counterbores 180 prior toinstallation of the differential assembly 54 in the differential housing70 between the first and second bearing journals 82 and 84.

Each adjuster 56 can include a body portion 190, an adjustment portion192 and a longitudinally extending bore 194 that can be formed throughthe adjuster 56. The body portion 190 can include an externally threadedportion 196 and a second bearing mount 198. The threaded portion 192 issized to be received in the threaded bore 94 and threadably engage anassociated one of the first and second bearing journals 82 and 84. Eachof the second bearing mounts 198 can be configured to receive acorresponding one of the second bearing portions 64. In the exampleprovided, the second bearing mount 194 is a hollow shaft and the secondbearing portion 64 includes a second bearing race 210, such as an innerbearing race, the can be press-fit onto the second bearing mount 198.The adjustment portion 192 can include a non-circular feature 212 thatis configured to be engaged by a tool (not shown) to rotate theadjusters 56 to both preload the differential bearings 60, as well as toset the lash between the pinion 52 and the ring gear 152 and/or adesired gear tooth contact pattern. For example, the non-circularfeature 212 can be a male feature that is sized to be engaged by a12-point socket for a socket wrench (i.e., a socket having a 12 sided ordouble-hex interior cavity). As those of skill in the art willappreciate, a 12-point socket can be employed to engage various types ofnon-circular male features, including those having four, six or twelveequal sides. In the particular example provided, the non-circularfeature 212 is a male 12-point structure (i.e., a male structure having12 equal sides).

The retaining members 58 can be configured to inhibit relative rotationbetween the adjusters 56 and the differential housing 70. The retainingmembers 58 can be formed of any suitable material, such as a powderedmetal material or a sheet or plate material, and have a circular shapewith a 12-point (i.e., 12-sided or double hex) hole 220 in its center.The 12-point hole 220 is configured to engage the non-circular feature212 on the adjustment portion 192 of the adjuster 56, while the outerdiameter of the retaining members 58 are sized to engage (via aninterference fit, such as a press-fit) the counterbores 100 in the firstand second bearing journals 82 and 84. It will be appreciated that asthe retaining members 58 are not “keyed” to the differential housing 70,the retaining members 58 can accommodate any orientation of thenon-circular feature 212 relative to the differential housing 70. Toaccommodate the disassembly of the front axle assembly 32, the retainingmembers 58 can include one or more removal apertures 228 that can besized to receive a tool (not shown) that can be employed to remove theretaining members 58 from the counterbores 100. The removal aperture 228can be sized to receive a removal tool or a portion thereof (such as ajaw) or could be threaded apertures to which the removal tool can becoupled.

The front axle assembly 32 can be assembled in part by installing thepinion 52 to the pinion bore 88 in the differential housing 70;positioning the differential assembly 54 (with the first bearingportions 62 coupled thereto) between the first and second bearingjournals 82 and 84 such that the first bearing portions 62 are alignedwith threaded bores 94 and the ring gear 152 is meshingly engaged to thepinion 52; inserting one of the adjusters 56 (with the second bearingportion 64 coupled thereto) through the axle shaft aperture 90 in thewall member 80 of the differential housing 70 and threadably engagingits threaded portion 192 to the threaded bore 94 in the first bearingjournal 82; inserting the other one of the adjusters 56 (with the secondbearing portion 64 coupled thereto) through the axle tube bore 92 in theaxle tube portion 76 and threadably engaging its threaded portion 192 tothe threaded bore 94 in the second bearing journal 84; rotating one orboth of the adjusters 56 to preload the differential bearings 60;rotating a position of one or both of the adjusters 56 as necessary toset the lash between the pinion 52 and the ring gear 152 and/or adesired gear tooth contact pattern; engaging the retaining members 58 tothe non-circular feature 212 on each of the adjusters 56; pressing eachof the retaining members 58 into an associated one of the counterbores100 such that the retaining member 58 non-rotatably engages thedifferential housing 70; installing a first axle shaft segment 250through the axle shaft aperture 90 and the longitudinally extending bore194 in the adjuster 56 that is located in the first bearing journal 82;coupling the first axle tube 72 to the differential housing 70; andinstalling axle shaft seals 300 into the first axle tube 72 and the axletube portion 76. Optionally, bearings 310 can be installed into thelongitudinally extending bore 194 in each of the adjusters 56 prior tothe installation of the seals 300, such as prior to the installation ofthe adjusters 56 to the axle housing 50. A second axle shaft segment 312can be received through the axle tube portion 76 and the longitudinallyextending bore 194 in the adjuster 56 that is located in the secondbearing journal 84. Each of the first and second axle shaft segments 250and 312 can be coupled for rotation with a respective one of the sidegears 172 (via a set of mating spline teeth) and a retaining ring 314can be employed to inhibit movement of the second axle shaft segment 312in a direction away from the side gear 172.

In the particular example provided, the front axle assembly 32 includesa third axle shaft segment 320 and a locking mechanism 322. The thirdaxle shaft segment 320 is received in the first axle tube 72 and can besupported by bearings 324 and 326 that are received in the first axleshaft segment 250 and the first axle tube 72, respectively. The lockingmechanism 322 can be employed to selectively couple the first and thirdaxle shaft segments 250 and 320 for rotation with one another. Thelocking mechanism 322 can include a coupling ring 330 and an actuator332 and can be housed in the first axle tube 72. The coupling ring 330can include a plurality of internal teeth 334, a set of spline teeth 336and an annular channel 338 that can extend about its circumference. Theinternal teeth 334 can be sized to matingly engage corresponding teeth340 that are formed on an end of the first axle shaft segment 250. Theset of spline teeth 336 can be matingly engaged to a set of matingspline teeth 342 that can be formed on the third axle shaft segment 320to permit the coupling ring 330 to be non-rotatably but axially slidablycoupled to the third axle shaft segment 320. The actuator 332 can be anytype of actuator that can move the coupling ring 330 between a firstposition, in which the internal teeth 334 are axially spaced apart fromthe teeth 340 on the first axle shaft segment 250, and a second positionin which the internal teeth 334 are meshingly engaged to the teeth 340on the first axle shaft segment 250. In the example provided, theactuator 332 includes a solenoid 350, a shifting fork 352 and a returnspring 354. The solenoid 350 can be received in a cavity 356 in thefirst axle tube housing 72 and can include a plunger 358 that can becoupled to the shifting fork 352. The shifting fork 352 can include apair of tines 360 that can be received into the annular channel 338 inthe coupling ring 330. The return spring 354 can be positioned to biasthe shifting fork 352 in a predetermined direction. The lockingmechanism 322 can be operated in a first condition to maintain thecoupling ring 330 in the first position to thereby decouple the thirdaxle shaft segment 320 from the differential assembly 54. The lockingmechanism 322 can also be operated in a second condition (e.g., byoperating the solenoid 350 to move the shifting fork 352 (via theplunger 358) so as to engage the internal teeth 334 of the coupling ring330 to the teeth 340 of the first axle shaft segment 250.

While specific examples have been described in the specification andillustrated in the drawings, it will be understood by those of ordinaryskill in the art that various changes may be made and equivalents may besubstituted for elements thereof without departing from the scope of thepresent disclosure as defined in the claims. Furthermore, the mixing andmatching of features, elements and/or functions between various examplesis expressly contemplated herein so that one of ordinary skill in theart would appreciate from this disclosure that features, elements and/orfunctions of one example may be incorporated into another example asappropriate, unless described otherwise, above. Moreover, manymodifications may be made to adapt a particular situation or material tothe teachings of the present disclosure without departing from theessential scope thereof. Therefore, it is intended that the presentdisclosure not be limited to the particular examples illustrated by thedrawings and described in the specification as the best mode presentlycontemplated for carrying out the teachings of the present disclosure,but that the scope of the present disclosure will include anyembodiments falling within the foregoing description and the appendedclaims.

1. An axle assembly comprising: an axle housing defining a pair ofbearing journals and a pinion bore, the differential bearing journalshaving a threaded bore formed therethrough that is generallyperpendicular to the pinion bore, each one of the differential bearingjournals having an outboard side opposite the other one of thedifferential bearing journals, a counterbore concentric with thethreaded bore being formed in each of the outboard sides; a pinionrotatably mounted in the pinion bore; a differential assembly having adifferential case, a gearset received in the differential case, and aring gear meshingly engaged to the pinion, the differential caseincluding a pair of bearing mounts; a pair of first bearing portionseach of which being coupled to an associated one of the bearing mountsand including a first bearing race and a set of bearing members that aremounted on a respective one of the first bearing races; a pair of hollowadjusters having a threaded body portion and an adjustment portion, eachof the hollow adjusters being coupled to the axle housing such that itsthreaded body portion is threadably engaged to the threaded bore of anassociated one of the differential bearing journals, the adjustmentportions having a non-circular feature that is adapted to be engaged bya tool for rotating the hollow adjusters; a pair of second bearingportions each having a second bearing race that is disposed between oneof the hollow adjusters and an associated one of the sets of bearingmembers; and a pair of retaining members, each retaining member beingreceived on an associated one of the hollow adjusters and engaging thenon-circular feature to inhibit relative rotation therebetween, each ofthe retaining members being press-fit into an associated one of thecounterbores to inhibit relative rotation between the retaining membersand the axle housing.
 2. The axle assembly of claim 1, wherein thesecond bearing races are press-fit to the hollow adjusters.
 3. The axleassembly of claim 1, wherein the non-circular feature is a male feature.4. The axle assembly of claim 3, wherein the male feature is capable ofbeing drivingly engaged by a 12 point socket wrench.
 5. The axleassembly of claim 1, wherein the retaining members are formed of amaterial selected from a group consisting of sheet materials, platematerials, powdered metal materials and combinations thereof.
 6. Theaxle assembly of claim 1, wherein the retaining members include aremoval aperture that is adapted to receive a removal tool that isconfigured to remove the retaining members from the axle housing.
 7. Theaxle assembly of claim 1, wherein the axle housing includes adifferential housing and a first axle tube, the differential bearingjournals being integrally formed with the differential housing, thefirst axle tube being separately formed and coupled to the differentialhousing.
 8. The axle assembly of claim 7, wherein the first axle tube isremovably coupled to the differential housing.
 9. The axle assembly ofclaim 7, wherein the axle housing includes a second axle tube.
 10. Theaxle assembly of claim 9, wherein the second axle tube is integrallyformed with the differential housing.
 11. The axle assembly of claim 10,wherein the second axle tube is shorter than the first axle tube. 12.The axle assembly of claim 10, further comprising a seal assemblyreceived in the second axle tube, the seal assembly being larger indiameter than a respective one of the hollow adjusters that is receivedthrough the second axle tube.
 13. The axle assembly of claim 1, whereineach of the differential bearing journals has a base portion and anintegrally-formed, non-separable cap portion.
 14. An axle assemblycomprising: an axle housing having a differential housing, a first axletube and a second axle tube, the differential housing defining a pair ofbearing journals and a pinion bore, the differential bearing journalsbeing integrally formed with the differential housing and non-separablefrom a remainder of the differential housing, the differential bearingjournals having a threaded bore formed therethrough that is generallyperpendicular to the pinion bore, the first axle tube being separatelyformed and removably coupled to the differential housing, the secondaxle tube being integrally formed with the differential housing andshorter than the first axle tube a pinion rotatably mounted in thepinion bore; a differential assembly having a differential case, agearset received in the differential case, and a ring gear meshinglyengaged to the pinion, the differential case including a pair of bearingmounts; a pair of first bearing portions each of which being coupled toan associated one of the bearing mounts and including a first bearingrace and a set of bearing members that are mounted on a respective oneof the first bearing races; a pair of hollow adjusters having a threadedbody portion and an adjustment portion, each of the hollow adjustersbeing coupled to the axle housing such that its threaded body portion isthreadably engaged to the threaded bore of an associated one of thedifferential bearing journals; a pair of second bearing portions, eachsecond bearing portion having a second bearing race that is press-fit toone of the hollow adjusters, the second bearing portions being disposedbetween the hollow adjusters the sets of bearing members; and a pair ofretaining members are received on the hollow adjusters and engage thenon-circular feature to inhibit relative rotation between the axlehousing and the hollow adjusters.
 15. The axle assembly of claim 14,wherein each one of the differential bearing journals has an outboardside opposite the other one of the differential bearing journals, andwherein a counterbore concentric with the threaded bore is formed ineach of the outboard sides.
 16. The axle assembly of claim 15, whereinthe retaining members are press-fit into the counterbores in thedifferential bearing journals to inhibit relative rotation between theretaining members and the axle housing.
 17. The axle assembly of claim14, further comprising a first output member, a second output member anda locking mechanism, the first output member being coupled to a firstoutput of the differential assembly, wherein the locking mechanismselectively couples the second output member to a second output of thedifferential assembly.